The rules say they must be entirely foam and tape. Is there anything we’re allowed to use to weight them to make them throw better? Caulk, birdseed, ect?
You could try an extra layer of tape in strategic spots. (Just make sure it stays safe.)
Note that we’ve approved and used commercial throwing boffers, both latex and injected foam (like calimacil). Some of them probably have foam that is more dense than the usual pipe insulation.
You could experiment with things like an internal birdseed pouch, but it’ll need to pass safety inspection regardless, and if it hits too hard, it hits too hard (‘hitting too hard’ being a common risk with trying to make them ‘throw better’).
Ok, cool. The foam company sent me I think half again as much foam as I actually ordered, so I have extra to experiment with. Thanks.